Benton City, WA 99320 Frost Dates
Benton City, WA: when does the frost end?
Typically, the last spring freeze lands around 04/06, roughly 221 days out. Fall's first freeze usually shows up around 10/24, roughly 200 days after the last spring frost.
Zone 7b (5 to 10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Benton City, not a forecast for this year.
Stretching the season past the first frost
With roughly 8 weeks until Benton City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Benton City's last frost
04/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/24 and only about 1 year in 10 sees frost after that.
Benton City against the rest of the dataset
Benton City's growing season runs about 200 days, ranking 17,785 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 320 of 700.
Learn more
Before leaning on 99320's figures: the frost range explains how to read the range around Benton City's dates instead of trusting one, while local microclimates explains what one yard in Benton City can differ from the 99320 normal.